Tag: science
The Gut Micro Bio-What?
1. What is the Gut Micro Biome?
Our body is a plethora of bugs! These microbes have incredibly diverse and essential roles in the way we thrive and function day to day, including but certainly not limited to, the digestion of food as well as hormone production. What we are more recently beginning to discover is that the gut micro biome is not only as unique in individuals as our fingerprints, it can also have an enormous impact on our health and longevity. It’s time to realise that our gut is much more than just a pipe for our food to move through, a place of nutrient absorption, or something we rub after regrettably overeating at dinner – our gut is a key director in our health. In fact, there are over 100 million neurone in the gut, which is more than our spinal cord (1)!
2. The Role of the Gut in Modern Chronic Disease
Why all this sudden interest in the gut micro biome? Common features of metabolic and inflammatory diseases such as diabetes, obesity and cardiovascular disease include an altered gut microbiota composition and a pro-inflammatory state (2). Additionally, it is now being understood that specific microbiota profiles can predispose us to obesity and weight gain (3). It is also known that the gut itself has a direct impact on the health of the brain, and the production of cytokines within the gut can cause the brain to produce more cortisol (4). Cortisol is the most commonly known stress hormone and a very serious contributor to the chronic conditions mentioned. It is revitalising to know that there is so much more we can do to combat these pulsing epidemics. For so long we’ve been looking in the wrong places for the answers to today’s health problems. It’s time to look in the gut.
3. Problems with Current Diet and Lifestyle
So what’s the problem then – why are our guts not healthy? Environmental stressors including Westernised diets, sedentary lifestyles, high pressure careers, lack of sleep, overuse of prescription medications alongside toxins in food, water and air have created an incongruity between our genome and what our body is actually expecting (4). We’ve already mentioned that our gut is capable of stimulating the production of cortisol, but what is more concerning is the cyclic effect of cortisol back on the gut. Cortisol increases the permeability (leakiness) of our intestinal walls and can negatively disrupt the balance of organisms that reside both inside and outside the gut. Every structure and function of the body works very differently when the body is under stress, and regulating the adrenals to achieve a place of balance is of uttermost importance for someone who has poor gut health.
4. The Stages of Gut Healing
The great news about all of this is that the solutions to gut health, though individual, tend to be a reversion back to whole, tasty and nutrient-dense foods parallel to practices that reduce life stressors. Healing the gut can result in the remission of inflammation and autoimmune symptoms such as joint pain, fatigue and bloating. However, it is important not to jump into using conventional measures to “fix” your gut (e.g probiotic supplementation) if you have existing poor gut health. As such, the general process of healing comes in two stages; stage 1) reducing pathogenic bacteria to relieve symptoms and heal the gut, and stage 2) repopulating bacteria into the gut with a diet as diverse as possible. The more gut imbalances one has (e.g. inflammatory bowel disease, irritable bowel syndrome), the better they do on a low-fibre, low-prebiotic diet initially (4). Prebiotics are compounds that feed and encourage bacterial growth and foods containing natural prebiotics include onions, garlic, broccoli, cabbage, wheat plus more. The challenge lies in identifying the stringency of restriction during the gut healing phase (stage 1) and pinpointing how and when the micro biome should be repopulated (stage 2). As such, a specialised dietitian is a useful partner in your individual gut microbiota investigation.
5. Diet Patterns for Optimisation of Gut Micro Biome Health
So once we’ve healed the gut, how can we achieve and maintain optimal gut health? A few well-known diet trends and lifestyles have proven their effectiveness when it comes to the species and diversity of the microbes within us. Firstly, a high-fibre diet is key. The average omnivore consumes about 19 grams of fibre each day, the average vegan consumes 43 grams, while contemporary hunter-gatherer societies may consume upwards of 100 grams daily (3, 5)! Fibre is what feeds the beneficial bacteria and a low intake tends to result from monotonous diets with poor vegetable consumption. The more diverse the diet, the more diverse the micro biome and the more resilient it becomes to disturbances (6). Modern dietary choices that exclude animal or plant products will narrow the gastrointestinal micro biome and may be the silent blockade to optimal health for millions of people (6). Diets that have proven beneficial for gut health include; Paleo, autoimmune Paleo, low FODMAP, intermittent fasting, low-carb high-fat, and even some gluten-free diets. All of these dietary patterns remove a lot of the foods that are toxic to our gut, including acellular carbohydrates which feed the harmful bacteria and cause dysbiosis (e.g. white flour, sugar, processed/refined foods) (3). It should be understood that in terms of gut healing (stage 1), low FODMAP diets are the most effective, yet for long term optimisation, individualisation is key and there is no “one size fits all”.
Bibliography
1. Liu G. What is your gut telling you? [Video]. Austin: Paleo f(x); 2016.
2. Saita D, Ferrarese R, Foglieni C, Esposito A, Canu T, Perani L, et al. Adaptive immunity against gut microbiota enhances apoE-mediated immune regulation and reduces atherosclerosis and western-diet-related inflammation. Scientific reports. 2016;6:29353.
3. Kresser C. What is your gut telling you? [Video]. Austin: Paleo f(x); 2016.
4. Perlmutter D. What is your gut telling you? [Video]. Austin: Paleo f(x); 2016.
5. Leach J. Paleo versus vegetarian – who eats more fiber? [Internet]. 2015 [cited 2016 10 Jul]. Available from: http://humanfoodproject.com/paleo-versus-vegetarian-who-eats-more-fiber/.
6. Heiman ML, Greenway FL. A healthy gastrointestinal microbiome is dependent on dietary diversity. Molecular Metabolism. 2016;5(5):317-20.
The Ketogenic Diet: Let’s Chew Through The Fat
I was recently approached to discuss the popular Ketogenic Diet. So let’s cut to the chase and chew through the fat.
When you ask your doctor about ketosis or when you type ketosis into Google search, the definition you will get is “a condition characterised by raised levels of ketone bodies in the blood, associated with abnormal fat metabolism and diabetes mellitus”.
However this definition is actually referring to a condition known as ketoacidosis which is a medical emergency signalled by raised ketone bodies in the absence of insulin. This is most common in the case of Type 1 diabetics who are not taking insulin correctly and not applicable to non-insulin requiring diabetics and the population at large, whose bodies are clearly able to produce insulin.
This misinformation surrounding ketosis is the frustrating reason why ketogenic diets are under-utilised as a therapeutic approach for modern day diseases.
What is ketosis?
Ketosis is a state where the body converts fats to ketone bodies to use as a primary fuel source in the absence of sufficient glucose. Whilst many people will tell you that your body needs glucose for energy – or prefers glucose as energy – your body and brain can run perfectly on blood ketones.
This state of ketosis is achieved by restricting carbohydrates and compensating with an increase in total fat intake (and yes, that includes saturated fats too) so our bodies can switch over from relying on carbohydrates as fuel to using fats as fuel.
Now you might be worried about saturated fats and its effect on your heart, but rest assured that the theorised link between saturated fat intake and heart disease is well and truly crumbling in the face of new scientific development, but this is honestly a topic for another time!
A typical ketogenic macronutrient split of proteins, carbohydrates and fats would be: 70%-75% fat | 20% protein | 5%-10% carbs
Why Ketosis?
Ketosis is an approach to eating that is much more than just another fad. When the body adapts to using fats as a primary fuel source, many benefits arise. Some of the most common ones include:
• Reduced sugar cravings due to eliminating insulin spikes and therefore blood glucose spikes and crashes associated with carbohydrate intake
• Increased satiety and therefore a reduced need and desire to snack constantly
• Reversal or control of Type 2 Diabetes and Insulin Resistance from eliminating the burden placed on the pancreas to secrete insulin constantly
• Fat loss from allowing the body to tap into their fat stores for energy, instead of forever accumulating fat stores whilst only ever using glucose and stored glycogen for fuel
• Reduced inflammation and inflammatory markers, and therefore an improvement in inflammation within the body including joints
• Improved blood lipid profile by increasing good healthy HDL, reducing unhealthy Triglycerides and improving overall total cholesterol to HDL ratio (which is a much greater predictor of heart health than total cholesterol alone)
Is the Ketogenic Diet for you?
Just like all dietary approaches, there is no one size fits all. However the ketogenic diet plan is fast become an approach that is helping people achieve better health long term.
Whilst it does encourage bringing fats back into the diet (and in quite high percentages too), it’s important that anyone considering this diet plan doesn’t lose focus on the quality of the food they are eating.
This approach is not a green light to eat a lot of fatty takeaway and junk food. Instead, it is about going back to basics, back to real foods.
It is saying: instead of highly-processed vegetable oils and margarines; instead of grain-fed hormone-injected meats and chickens; instead of processed packaged foods filled with omega-6 rich oils and trans fatty acids: opt for organic butters, coconut oils, natural nuts and seeds, oily fish, avocados, olive oils, grass-fed meats, organic chickens, free-range eggs, and so forth.
Not everyone needs to go on a ketogenic diet to see health benefits, however, the ketogenic diet has certainly shown much scientific validity, much popularity and much promise in helping individuals achieve overall better health.
The Real Skinny on Low Carb Diets – A Critique.
This is a Critique of “The Skinny on Low Carb Diets” by Jenelle Croatto. The original article found here: https://www.12wbt.com/blog/nutrition/the-skinny-on-low-carb-diets/
Before I start, I want to preface this by saying that this article is not intended to “carb-shame”, but rather present the facts, which unfortunately is so often neglected when writing about carbohydrates and diet.
DEFINING THE UNDEFINED
So often we hear of the term “Low-Carb” – low carb bars, low-carb breakfast cereals, low-carb pastas, low-carb diets….so, my first question is: what exactly is LOW carb?
Unfortunately, in Australia and around the world, there is no clear definition. One source will claim that the MINIMUM we should consume a day is 130g of carbohydrates (hence implying that anything below that is technically low carb). Another source will state that low carb is less than 20% daily intake (which for someone on a 2000kcal a day diet means 100g of carb versus for someone on a 1300kcal a day diet means 65g of carb). The most extreme sources I have come across suggest 10% of total daily energy from carbs (which using the above example of 2000kcal and 1300kcal a day means 50g and 30g respectively of carbs). For the sake of this article, I am going to adopt a somewhat middle ground and say 50-65g of carb a day is “Low Carb”
However, I am yet to come across a single source that suggest we eat ZERO carbs. So the first point I want to make is: when we are talking low carb, a) the definition varies dramatically, and b) we do NOT imply no carbs.
WHY WE DON’T NEED CARBS
- It is not a premium energy source, nor is it the only energy source
Our body uses carbs as the first line of energy because it is readily available and accessible. In a modern Western diet, carbohydrates are very abundant, so the body adapts to using exogenous glucose from carbohydrate foods as fuel. So – what happens when we don’t have much carbs in our diet? Our body can produce glucose endogenously via gluconeogenesis, a process whereby the body creates glucose using non-carbohydrate derivatives such as amino acids (from proteins) and lipids (from fats). The body can also produce ketones for energy, running the body on fat as fuel as opposed to glucose as fuel.
- It does not help with sugar cravings
When our body is running on fats as fuel, insulin and blood glucose levels are low and stable, hence eliminating the normal issues with sugar cravings, post prandial slumps and strange energy spikes and dips throughout the day. Also a diet high in protein and healthy fats are much more satiating anyway! Who has ever had eggs for breakfast and noticed they don’t feel the need to snack mid morning?
- It is not involved in fat burning, let alone optimises fat burning
One thing I want to clear up before proceeding is: reducing carbs does NOT mean necessarily reducing total calories. Reducing carbs simply means reducing the quantity of carbs, but one can still increase fats and proteins for energy and satiety.
Now, in contrast to this unreferenced “population study” that apparently shows that those who include wholegrains in their diets tend to have smaller waistlines and be leaner, I have a referenced study that shows the striking contrast in FAT loss for those on a low-carb diet, versus a low-fat diet. Furthermore, this study also showed improvements in risk levels for heart disease in the low-carb group versus the low-fat group (Bazzano, LA, et al. Effects of low-carbohydrate and low-fat diets: a randomized trial. Ann Intern Med. 2014 Sep 2;161(5):309-18.). So – do carbs optimize fat burning? Apparently not.
As for the sensationalist journalism used to compare “soft white bread” to “steak” when describing their “eatability versus satiability” – I don’t think I really need to comment here.
A FINAL NOTE ON FIBRE
I believe that fibre is very important for bowel health. I also believe that fibre does not require eating pasta to obtain (100g of cooked pasta only giving us 2g of fibre) which is no more than what 100g of green beans, carrots, broccoli or eggplant would provide (100g of each would give you 2-3g of fibre). In a day, we are recommended 30g of fibre – so the question is: can we meet this on a “low-carb” diet (remember, we are using 50-65g carb a day as a guide)? Let’s find out:
| Food | Quantity | Net carb | Fibre |
| Raspberries | 50g | 2.5g | 4g |
| Chia seeds | 1 tbsp | 1g | 3g |
| Green beans (as an example) | 200g | 7g | 7g |
| Black rice | 125g cooked | 26g | 4g |
| Psyllium husk | 1 tbsp | 0g | 10g |
| TOTAL | 36.5g | 28g |
The answer is: Yes.
The Bottom Line?
I am not writing this to advocate carbs one way or another for the general population. I am simply presenting facts and figures, and obviously, disagreeing with the general tone of the original article I am critiquing.
As dietitians we are there to educate and present our clients with facts so they can decide whether a low carb approach is for them or not. We should not form pre-conceived stances on these things and attempt to sway our clients one way or another based on our own beliefs.
